DDR running at diferent mHz on 2 Pc's..why??

[Brainless]

Hi

As the name states i'm brainless but i've just purchased 2 new memory modules(DDR's) 256@400mhz but when i plugged them in the the slots and go to set up they only run at 166mhz.......erh.....beats me......but when i plugged them same modules in to my kids PC it says they are 333mhz's. (now im losing it)

this PC is a new built one by myself. and both hav e GE-Pro mother boards and P4's (1 is 2.8 2nd 2.2)

if anyone can shed some light on this problem for me i would appreciate it

Many thanks

Mark

[WhatsThisBoxFor?]

The ram only runs at the speed of the fsb (front side bus) of the processor, which seems to be 533Mhz? (or 166 X 4)

[Brainless]

This Pentium 4 is 2.80cGHz 800MHz system bus and 512-KB L2 Adv transfer Cache. So it should be 200mHz???

Thanks

Mark

[WhatsThisBoxFor?]

If the fsb is 800, then yes to run the memory 1:1 it should be 200Mhz, look in the BIOS for RAM ratio, or RAM divider, and make sure that is set so the ram fsb is the same as the processor (i.e. 1:1).

[Brainless]

great..I'll check it again, Thanks for your help

Its appreciated..

Mark